The phrase “Frankenfood” entered tabloid English at the turn of the last century when protesters, backed by the green movement, trashed GM crops wearing white overalls and face masks as an emotive PR tactic.

Much of the early opposition to GM crops was aimed at multinational companies, especially Monsanto, whose heavy-handed approach to public concern stoked resentment and mistrust. When asked in 1998 about the safety of GM foods, one senior Monsanto figure in the US said: “Our interest is in selling as much of it as possible. Assuring its safety is the FDA’s job.”

Monsanto’s dismissive response was clumsy even for big business. The public sector scientists at Rothamsted Research, who are growing an experimental GM wheat crop with no commercial backing, are a different breed. When the anti-GM group, Take the Flour Back, declared a day of mass action to destroy their plants, they invited the protesters to discuss the work. They recorded a video, in which each scientist in turn appealed directly to the campaigners not to go through with their threat. They pleaded with them to at least spare an unrelated experiment, which began in the fields around Rothamsted in 1843.

The campaigners’ response was to propose a public debate at a neutral venue, where both sides could argue their case. The scientists agreed and offered to pay for the event, only for the campaigners to pull out days later.

This was a new strategy for crop scientists, born though it was from desperation. When protesters threatened GM trials before, many researchers simply kept their heads down and their fingers crossed. The fate of their trials was left to the local constabulary. The Rothamsted scientists have won public support. In stark contrast to the 1990s, the media overwhelmingly condemned the campaigners’ threat of vandalism.

The GM wheat at Rothamsted is modified to produce a scent undetectable to the human nose, which the main wheat pests, such as greenfly and blackfly aphids, release when under attack from predators. The chemical acts as an alarm call that prompts other aphids to scarper. Some 400 plant species, including peppermint, make the same chemical, although whether it serves to protect them from pests is not entirely clear.

The GM wheat trial hopes to find answers to many questions. Does a crop that produces a steady waft of aphid alarm pheromone repel the pests? Or are the insects indifferent if the chemical is not released in bursts, as happens in nature? Does the pheromone attract aphid predators to the crops, as suspected? Can the wheat be grown with less pesticide? What are the knock-on effects on other organisms? The viability, and acceptability, of the crop rests on the answers to these questions. The protesters object to the trial on a multitude of grounds. They claim the crops are not proven safe, to people or to the environment. They fear it will not reduce pesticide usage, that the GM strain will ultimately be commercialised by industry, and that it could lead to contamination.